Photopolymerization of ethylenically unsaturated monomers

Abstract

An initiator-free composition is prepared of an ethylenically unsaturated monomer and the inhibitor parabenzoquinone or hydroquinone. The composition is irradiated with light having a wavelength within the absorption spectrum of the inhibitor, other than ultraviolet. The light causes the inhibitor to produce a reactive species which initiates polymerization.

I claim: 
     
       1. A method of photopolymerizing an ethylenically unsaturated monomer comprising (1) preparing a composition of an ethylenically unsaturated monomer and at least about 0.1 mole percent of an inhibitor selected from the group consisting of parabenzoquinone, hydroquinone, and mixtures thereof, said composition being free of any photoinitiator; and   (2) irradiating said composition with light having a wavelength within the absorption band of said inhibitor, said wavelength being outside of the ultraviolet band.   
     
     
       2. A method according to claim 1 wherein said monomer is a polyfunctional acrylate. 
     
     
       3. A method according to claim 2 wherein said polyfunctinal acrylate is selected from the group consisting of hexanedioldiacrylate, trimethylolpropanetriacrylate, and tetraethyleneglycoldiacrylate. 
     
     
       4. A method according to claim 1 wherein said inhibitor is parabenzoquinone. 
     
     
       5. A method according to claim 1 wherein said wavelength is between about 480 and about 515 μm. 
     
     
       6. A method according to claim 1 wherein said composition is solventless. 
     
     
       7. A method according to claim 1 wherein said monomer is a liquid. 
     
     
       8. A method according to claim 1 wherein the amount of said inhibitor is about 0.1 to about 2.0 mole percent. 
     
     
       9. A method according to claim 8 wherein the amount of said inhibitor is about 1.0 to about 2.0 mole percent. 
     
     
       10. A polymer made according to the method of claim 1.